Three-dimensional hollow high-dispersion metal catalyst and preparation method thereof

Abstract

The invention discloses a three-dimensional hollow high-dispersion metal catalyst and a preparation method thereof, and belongs to the technical field of industrial catalysis. The preparation method comprises the following steps of: preparing a three-dimensional hollow bimetallic oxide by a microwave hydrothermal method; carrying out oxygen plasma based modification and silane coupling agent basedsurface hydrophobic modification on the bimetallic oxide to obtain a modified three-dimensional hollow bimetallic oxide carrier; adding an active component nickel salt, an auxiliary agent group IVA element metal salt and a rare earth element metal salt; loading the active component and the auxiliary agent metal on the modified carrier by adopting a photodeposition technology; and carrying out roasting in an air flow at 400-600 DEG C to obtain the three-dimensional hollow high-dispersion metal catalyst. Based on the total mass of the catalyst, the catalyst comprises 20-40wt% of nickel, 0.01-5wt% of IVA group element metal and 0.01-5wt% of rare earth element metal. The catalyst is applied to catalyzing pyridine dehydrogenation coupling to synthesize 2, 2'-dipyridyl, has the advantages of low catalyst dosage, few side reactions, short process and the like, and has a good industrial application prospect.

Description

technical field [0001] The invention belongs to the technical field of industrial catalysis, and in particular relates to a three-dimensional hollow highly dispersed metal catalyst and a preparation method thereof. Background technique [0002] 2,2'-bipyridine is one of the important isomers of bipyridine. As an important chemical basic raw material, it is widely used in organic synthesis, "three medicines" preparation, heavy metal ion detection indicator, chemical copper plating additive Wait. Therefore, the research and development of high-efficiency, safe and low-pollution 2,2'-bipyridine green synthesis catalysts has important industrial application value. [0003] At present, the synthetic methods of 2,2'-bipyridyl mainly include the cyclization method of pyridine carbonyl compound in U.S. Patent US4147874A, the Ullmann method of Chinese patent CN107935919A, the direct dehydrogenation coupling method of Chinese patent CN105461620A, etc., wherein the pyridine carbonyl c...

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Problems solved by technology

[0003] At present, the synthetic methods of 2,2'-bipyridyl mainly include the cyclization method of pyridine carbonyl compound in U.S. Patent US4147874A, the Ullmann method of Chinese patent CN107935919A, the direct dehydrogenation coupling method of Chinese patent CN105461620A, etc., wherein the pyridine carbonyl compound The cyclization method has been eliminated due to the problems of expensive pyridine carbonyl compounds, high reaction temperature, and many by-products. Although the Ullmann method is relatively mature, the reaction route is long, the production efficiency is low, and there are still halogens in the production process. The reactants have hidden dangers of environmental pollution and do not meet the requirements of green chemical production. The direct dehydrogenation coupling method to synthesize 2,2'-bipyridine has a short synthesis route, less side reactions, and is environmentally friendly. The key to the final industrial application of this method is research and development. Efficient dehydrogenation coupling catalyst

[0004] U.S. Patent US3152137 discloses a preparation method of Raney nickel catalyst, which mainly adjusts the ratio of nickel-aluminum alloy to optimize the preparation method of the catalyst. high efficiency, but the prepared catalyst is poor in safety, highly prone to spontaneous combustion, short in catalyst life, easy to deactivate, and has many side reactions and complicated products; Any two combinations of non-noble metals Ni, Cu, Fe, Zn, and Co are active metals, supported by alumina as a supported bimetallic nanocatalyst, which is used in the direct dehydrogenation coupling of pyridine to produce 2,2'-bipyridine reaction , the preparation process of the catalyst is simple, but the amount of catalyst used is large, which leads to an increase in the cost of the catalyst, and the dispersion of the active metal on the carrier is low, the interaction between the active metal and the carrier is weak, and the active component is easy to lose during the reaction process. Catalytic activity declines; Chinese patent CN107935919A discloses a kind of 2 o 3 -SiO 2 -MgO-supported nickel, manganese, lanthanum, and cerium dehydrogenation catalysts are used for pyridine dehydrogenation coupling to prepare 2,2'-bipyridine. This patent mainly screens the active components of the catalyst. The currently reported pyridine Most of the dehydrogenation coupling reaction to prepare 2,2'-bipyridine adopts tank-type batch reaction, and the amount of catalyst is large. Therefore, it is suitable to develop a fixed-bed reactor with low catalyst amount, less side reactions, and a short process for direct dehydrogenation coupling. Efficient catalysts for synthesizing 2,2'-bipyridines are of great significance